1. Field of the Invention
The present invention relates to a method in which recording paper such as thermosensitive recording paper wound on a roll is cut off by a cutter after recording is performed on a one-sheet area of the paper.
2. Description of the Prior Art
In FIG. 1, numeral 1 denotes a roll-wound thermosensitive recording paper provided in a prescribed housing portion and platen roller 2 is for feeding the recording paper. Thermosensitive head 3 has a heating portion 3a in the face of the platen roller and is put in contact with the roller under prescribed pressure so as to record information on the recording paper. Electric motor 4 has gear train 5 comprising gears 5a, 5b, 5c and 5d to transmit the torque of the motor 4 to the platen roller to rotate it at a lower speed than the motor. Cutter 6 is for cutting off the recording paper after the information is recorded on one-sheet of paper.
The operation of the conventional facsimile apparatus will be described with reference to FIG. 1, FIG. 2 which is a time chart, and FIG. 3 which is a flow chart. In FIG. 2, (A) designates the timing of the recording by the thermosensitive head 3, (B) designates the operation of the motor 4, and (C) designates the operation of the cutter 6. In FIG. 2, S denotes the time which it takes for the recording paper 1 to move through the distance D (which is shown in FIG. 1) from the heating portion 3a of the thermosensitive head 3 to the cutter 6. Period E represents the time of the operation of the cutter, and F represents the time of the stoppage of the recording by the head 3. When the motor 4 is rotated forward in a direction G shown in FIG. 1 (in FIG. 2 shown as FORWARD), the platen roller 2 is turned in a direction H through the gear train 5 so that the recording paper 1 is fed in a direction I. At the same time, the thermosensitive head 3 is turned on so that information is recorded on the nth-sheet area of the paper 1. The paper is then fast fed forward by the distance D (in FIG. 3, shown as F--F) for a portion of the time F so that the trailing edge of the nth-sheet area of the paper is stopped at the cutter 6. After the stoppage of the motor 4 is confirmed, the cutter 6 is put into operation to cut off the recording paper 1. Subsequently, the motor 4 is rotated backward in a direction J (in FIG. 2, shown as REVERSE) so that the platen roller 2 is turned in a direction K through the gear train 5 so that the recording paper is pulled back by the distance D in the direction L. The motor 4 is then set to rotate forward in the direction G so that the recording paper 1 is fed in the direction I. At the same time, the thermosensitive head 3 is turned on so that information is recorded on the (n+1)th-sheet area of the recording paper 1. The time F of the stoppage of the recording, as illustrated in FIG. 2, is expressed as follows: EQU F=S+E+S (1)
The conventional operation of the thermosensitive head 3, the motor 4, the cutter 6 and the other interacting elements is regulated, for the sequence shown in FIG. 2, by a control circuit including a microcomputer or the like not shown in the drawings. FIG. 3 is a flow chart illustrating the steps of the conventional paper cutting method as described above.
FIG. 4 is a side view of a major part of another conventional facsimile apparatus. In FIG. 4, numerals 7a and 7b designate timing pulleys, and 8 is a timing belt for rotating a platen roller 2 through the timing pulleys 7a and 7b by the rotation of a motor 4. Except the platen roller drive mechanism of the apparatus, the arrangement of FIG. 4 is the same as that shown in FIG. 1.
The operation of the apparatus shown in FIG. 4 will be described with reference to FIG. 5 which is a time chart. In FIG. 5, T denotes the time of the stoppage of recording by thermosensitive head 3. When the motor 4 is rotated forward in a direction V shown in FIG. 4, (in FIG. 5, shown as FORWARD) the platen roller 2 is rotated in a direction H through the timing pulleys 7a and 7b and the timing belt 8 so that thermosensitive recording paper 1 wound on a roller is fed in a direction I. At the same time, the thermosensitive head 3 is turned on so that information is recorded on the nth-sheet area of the paper 1. After the information is recorded on the nth-sheet area of the paper 1, the recording of information on the (n+1) th-sheet area of the paper is started. As the recording of the information on the (n+1)th-sheet area of the paper 1 continues, the nth-sheet of paper 1 moves forward by the distance D from the heating portion 3a of a thermosensitive head 3 to a cutter 6. The motor 4 is stopped as well as recording on the (n+1)th-sheet. The cutter 6 is thereafter put into operation to cut off the recording paper 1. The thermosensitive head 3 is then turned on so that the recording of the information on the (n+1)th-sheet area of the recording paper 1 is resumed. The time T of the stoppage of the recording, as illustrated in FIG. 5, is expressed as follows: EQU T=E (2)
In the facsimile apparatus as shown in FIG. 1, the recording on the (n+1)th-sheet area of the recording paper 1 is started after the completion of the recording on the nth-sheet area, and after the nth-sheet area is cutoff. This procedure is to insure that the recorded image on the (n+1)th-sheet area of the paper is not disturbed due to the backlash of the gear train 5. Backlash of the gear train results from the paper being pulled forward in direction I by the cutting action of cutter 6. When recording resumes, the motor 4 moves gear 5c a distance, equal to the amount gear 5d was rotated forward, before engaging gear 5d and advancing the paper. This distance is equal to the distance between the teeth of gears 5d and 5c. The time required to move this distance results in blank spaces or overlapping recordings on the (n+1)th-sheet. For that reason, the trailing edge of the nth-sheet area of the recording paper is once quickly moved to the cutter 6, and cut off thereby. The leading edge of the (n+1)th-sheet area of the paper is then moved back toward the thermosensitive head 3, as shown in FIG. 2. Fast feeding, stopping and reversing paper 1 results in lengthening the time from the end of the recording on the nth-sheet area of the paper 1 to the start of the recording of the (n+1)th-sheet area. Therefore, it takes a long time to perform communication to the facsimile apparatus through a telephone line. High communication costs result from this problematic method of cutting off a recorded area of paper 1.
In the conventional facsimile apparatus shown in FIG. 4, since the torque of a gear is transmitted to the platen roller 2 through the timing pulleys 7a and 7b and timing belt 8, the recorded image on the (n+1)th-sheet area of the recording paper 1 is not disturbed by backlash. For that reason, the time from the end of the recording on the nth-sheet area of the recording paper 1 to the start of the recording on the (n+1)th-sheet area thereof is shorter, as shown in FIG. 5. Therefore, it takes a shorter time to perform communication to the facsimile apparatus of FIG. 4 through a telephone line. However, since the tension of the timing belt needs to be adjusted in installing the electric motor, the facsimile apparatus of the type shown in FIG. 4 has a problem in that the efficiency of its manufacturing is low.